The present disclosure relates to an image reading device and an image forming apparatus.
Conventionally, there is known an image reading device configured to read a document so as to generate image data. This image reading device is mounted, for example, on an image forming apparatus configured to print an image on a paper sheet. In addition, the image reading device includes a contact glass having a document placing surface on which a document is placed, a lamp for emitting light for irradiating the document, an image sensor configured to receive light reflected by the document so as to read the document, and the like.
Along a pair of sides extending in a main scanning direction and in a sub-scanning direction of the document placing surface, there are disposed document scales for regulating a position at which the document is placed within the document placing surface. The document scales are indexes for aligning a corner of the document to a predetermined reference point to which the corner of the document should be aligned within the document placing surface. For instance, an intersection between the document scale extending in the main scanning direction and the document scale extending in the sub-scanning direction is the reference point. In this case, the document is set to abut the document scales, and hence a corner of the document can be easily aligned to the reference point.
There is an image reading device having a special mode in which a predetermined point apart from the document scales within the document placing surface is set as the reference point (to which a corner of the document should be aligned) for reading the document. In the image reading device having this special mode, in order that the user recognizes the reference point (predetermined point) for the special mode, marks indicating positions in the main scanning direction and in the sub-scanning direction of the reference point for the special mode are provided to the document scales, for example. However, for the user who wants to read a document in the special mode, even if the marks indicating the position of the reference point (predetermined point) for the special mode are provided to the document scales, it is difficult to align a corner of the document to the reference point (predetermined point) for the special mode, because the reference point (predetermined point) for the special mode is apart from the document scales.